dom/base/LinkStyle.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6 #ifndef mozilla_dom_LinkStyle_h
   7 #define mozilla_dom_LinkStyle_h
   8
   9 #include "nsINode.h"
  10 #include "mozilla/Attributes.h"
  11 #include "mozilla/StyleSheet.h"
  12 #include "mozilla/Result.h"
  13 #include "mozilla/Unused.h"
  14 #include "nsTArray.h"
  15
  16 class nsIContent;
  17 class nsICSSLoaderObserver;
  18 class nsIPrincipal;
  19 class nsIURI;
  20
  21 namespace mozilla {
  22
  23 namespace dom {
  24
  25 class Document;
  26 class ShadowRoot;
  27
  28 // https://drafts.csswg.org/cssom/#the-linkstyle-interface
  29 class LinkStyle {
  30  public:
  31   enum class ForceUpdate : uint8_t {
  32     No,
  33     Yes,
  34   };
  35
  36   enum class Completed : uint8_t {
  37     No,
  38     Yes,
  39   };
  40
  41   enum class HasAlternateRel : uint8_t {
  42     No,
  43     Yes,
  44   };
  45
  46   enum class IsAlternate : uint8_t {
  47     No,
  48     Yes,
  49   };
  50
  51   enum class IsInline : uint8_t {
  52     No,
  53     Yes,
  54   };
  55
  56   enum class IsExplicitlyEnabled : uint8_t {
  57     No,
  58     Yes,
  59   };
  60
  61   enum class MediaMatched : uint8_t {
  62     Yes,
  63     No,
  64   };
  65
  66   struct Update {
  67    private:
  68     bool mWillNotify;
  69     bool mIsAlternate;
  70     bool mMediaMatched;
  71
  72    public:
  73     Update() : mWillNotify(false), mIsAlternate(false), mMediaMatched(false) {}
  74
  75     Update(Completed aCompleted, IsAlternate aIsAlternate,
  76            MediaMatched aMediaMatched)
  77         : mWillNotify(aCompleted == Completed::No),
  78           mIsAlternate(aIsAlternate == IsAlternate::Yes),
  79           mMediaMatched(aMediaMatched == MediaMatched::Yes) {}
  80
  81     bool WillNotify() const { return mWillNotify; }
  82
  83     bool ShouldBlock() const {
  84       if (!mWillNotify) {
  85         return false;
  86       }
  87
  88       return !mIsAlternate && mMediaMatched;
  89     }
  90   };
  91
  92   static LinkStyle* FromNode(nsINode& aNode) { return aNode.AsLinkStyle(); }
  93   static const LinkStyle* FromNode(const nsINode& aNode) {
  94     return aNode.AsLinkStyle();
  95   }
  96
  97   static LinkStyle* FromNodeOrNull(nsINode* aNode) {
  98     return aNode ? FromNode(*aNode) : nullptr;
  99   }
 100
 101   static const LinkStyle* FromNodeOrNull(const nsINode* aNode) {
 102     return aNode ? FromNode(*aNode) : nullptr;
 103   }
 104
 105   enum RelValue {
 106     ePREFETCH = 0x00000001,
 107     eDNS_PREFETCH = 0x00000002,
 108     eSTYLESHEET = 0x00000004,
 109     eNEXT = 0x00000008,
 110     eALTERNATE = 0x00000010,
 111     ePRECONNECT = 0x00000020,
 112     // NOTE: 0x40 is unused
 113     ePRELOAD = 0x00000080
 114   };
 115
 116   // The return value is a bitwise or of 0 or more RelValues.
 117   static uint32_t ParseLinkTypes(const nsAString& aTypes);
 118
 119   void UpdateStyleSheetInternal() {
 120     Unused << UpdateStyleSheetInternal(nullptr, nullptr);
 121   }
 122
 123   struct MOZ_STACK_CLASS SheetInfo {
 124     nsIContent* mContent;
 125     // FIXME(emilio): do these really need to be strong refs?
 126     nsCOMPtr<nsIURI> mURI;
 127
 128     // The principal of the scripted caller that initiated the load, if
 129     // available. Otherwise null.
 130     nsCOMPtr<nsIPrincipal> mTriggeringPrincipal;
 131     nsCOMPtr<nsIReferrerInfo> mReferrerInfo;
 132     mozilla::CORSMode mCORSMode;
 133     nsString mTitle;
 134     nsString mMedia;
 135     nsString mIntegrity;
 136     nsString mNonce;
 137
 138     bool mHasAlternateRel;
 139     bool mIsInline;
 140     IsExplicitlyEnabled mIsExplicitlyEnabled;
 141
 142     SheetInfo(const mozilla::dom::Document&, nsIContent*,
 143               already_AddRefed<nsIURI> aURI,
 144               already_AddRefed<nsIPrincipal> aTriggeringPrincipal,
 145               already_AddRefed<nsIReferrerInfo> aReferrerInfo,
 146               mozilla::CORSMode, const nsAString& aTitle,
 147               const nsAString& aMedia, const nsAString& aIntegrity,
 148               const nsAString& aNonce, HasAlternateRel, IsInline,
 149               IsExplicitlyEnabled);
 150
 151     ~SheetInfo();
 152   };
 153
 154   virtual nsIContent& AsContent() = 0;
 155   virtual Maybe<SheetInfo> GetStyleSheetInfo() = 0;
 156
 157   /**
 158    * Used to make the association between a style sheet and
 159    * the element that linked it to the document.
 160    *
 161    * @param aStyleSheet the style sheet associated with this
 162    *                    element.
 163    */
 164   void SetStyleSheet(StyleSheet* aStyleSheet);
 165
 166   /**
 167    * Tells this element to update the stylesheet.
 168    *
 169    * @param aObserver    observer to notify once the stylesheet is loaded.
 170    *                     This will be passed to the CSSLoader
 171    */
 172   Result<Update, nsresult> UpdateStyleSheet(nsICSSLoaderObserver*);
 173
 174   /**
 175    * Tells this element whether to update the stylesheet when the
 176    * element's properties change.
 177    *
 178    * @param aEnableUpdates update on changes or not.
 179    */
 180   void SetEnableUpdates(bool aEnableUpdates) {
 181     mUpdatesEnabled = aEnableUpdates;
 182   }
 183
 184   /**
 185    * Gets the charset that the element claims the style sheet is in.
 186    * Can return empty string to indicate that we have no charset
 187    * information.
 188    *
 189    * @param aCharset the charset
 190    */
 191   virtual void GetCharset(nsAString& aCharset);
 192
 193   // This doesn't entirely belong here since they only make sense for
 194   // some types of linking elements, but it's a better place than
 195   // anywhere else.
 196   void SetLineNumber(uint32_t aLineNumber) { mLineNumber = aLineNumber; }
 197
 198   /**
 199    * Get the line number, as previously set by SetLineNumber.
 200    *
 201    * @return the line number of this element; or 1 if no line number
 202    *         was set
 203    */
 204   uint32_t GetLineNumber() const { return mLineNumber; }
 205
 206   // This doesn't entirely belong here since they only make sense for
 207   // some types of linking elements, but it's a better place than
 208   // anywhere else.
 209   void SetColumnNumber(uint32_t aColumnNumber) {
 210     mColumnNumber = aColumnNumber;
 211   }
 212
 213   /**
 214    * Get the column number, as previously set by SetColumnNumber.
 215    *
 216    * @return the column number of this element; or 1 if no column number
 217    *         was set
 218    */
 219   uint32_t GetColumnNumber() const { return mColumnNumber; }
 220
 221   StyleSheet* GetSheet() const { return mStyleSheet; }
 222
 223   /** JS can only observe the sheet once fully loaded */
 224   StyleSheet* GetSheetForBindings() const;
 225
 226  protected:
 227   LinkStyle();
 228   virtual ~LinkStyle();
 229
 230   // Gets a suitable title and media for SheetInfo out of an element, which
 231   // needs to be `this`.
 232   //
 233   // NOTE(emilio): Needs nsString instead of nsAString because of
 234   // CompressWhitespace.
 235   static void GetTitleAndMediaForElement(const mozilla::dom::Element&,
 236                                          nsString& aTitle, nsString& aMedia);
 237
 238   // Returns whether the type attribute specifies the text/css type for style
 239   // elements.
 240   static bool IsCSSMimeTypeAttributeForStyleElement(const Element&);
 241
 242   // CC methods
 243   void Unlink();
 244   void Traverse(nsCycleCollectionTraversalCallback& cb);
 245
 246   /**
 247    * @param aOldDocument   should be non-null only if we're updating because we
 248    *                       removed the node from the document.
 249    * @param aOldShadowRoot should be non-null only if we're updating because we
 250    *                       removed the node from a shadow tree.
 251    * @param aForceUpdate true will force the update even if the URI has not
 252    *                     changed.  This should be used in cases when something
 253    *                     about the content that affects the resulting sheet
 254    *                     changed but the URI may not have changed.
 255    *
 256    * TODO(emilio): Should probably pass a single DocumentOrShadowRoot.
 257    */
 258   Result<Update, nsresult> UpdateStyleSheetInternal(
 259       Document* aOldDocument, ShadowRoot* aOldShadowRoot,
 260       ForceUpdate = ForceUpdate::No);
 261
 262   /**
 263    * @param aOldDocument should be non-null only if we're updating because we
 264    *                     removed the node from the document.
 265    * @param aOldShadowRoot The ShadowRoot that used to contain the style.
 266    *                     Passed as a parameter because on an update, the node
 267    *                     is removed from the tree before the sheet is removed
 268    *                     from the ShadowRoot.
 269    * @param aForceUpdate true will force the update even if the URI has not
 270    *                     changed.  This should be used in cases when something
 271    *                     about the content that affects the resulting sheet
 272    *                     changed but the URI may not have changed.
 273    */
 274   Result<Update, nsresult> DoUpdateStyleSheet(Document* aOldDocument,
 275                                               ShadowRoot* aOldShadowRoot,
 276                                               nsICSSLoaderObserver*,
 277                                               ForceUpdate);
 278
 279   RefPtr<mozilla::StyleSheet> mStyleSheet;
 280   nsCOMPtr<nsIPrincipal> mTriggeringPrincipal;
 281   bool mUpdatesEnabled;
 282   uint32_t mLineNumber;
 283   uint32_t mColumnNumber;
 284 };
 285
 286 }  // namespace dom
 287
 288 }  // namespace mozilla
 289
 290 #endif  // mozilla_dom_LinkStyle_h